The present invention relates to a compressor which is generally used for an air conditioner.
Various types of compressors are used in air conditioners. Among these compressors, particularly, a piston-type variable displacement compressor has an advantage that its displacement or flow rate can be varied. However, since the piston-type variable displacement compressor has a characteristic that the volume of gas passing through a suction valve during the flow rate of the suction valve is low is decreased, the suction valve generates self-excited vibration in its free movement region due to the interaction with the gas passing through the suction valve. The self-excited vibration of the suction valve causes pressure fluctuation of gas i.e. pressure pulsation. Since the compressor is included in a refrigerating cycle together with an evaporator, a condenser, and connecting pipes therebetween, the pressure pulsation is propagated to the evaporator through the connecting pipes from the compressor. As a result, the evaporator is vibrated, thereby producing noise.
Conventionally, to restrain the propagation of pressure pulsation to the evaporator, such a refrigerating cycle is provided with a silencer on the way of the connecting pipes.
However, the way of providing with a silencer has a lot of side issues, such as, making the system expensive, making a space factor worse, and requiring improved vibration proof of the silencer.